This invention pertains to a plural-priority-categorized, wireless network communication, and in particular to structure and methodology which promote a rapid build-up of transmission-limit settings in participating basic service set (BSS) stations operating in such a network. As will be explained, it is these transmission-limit settings which play important roles in the speeds with which currently non-transmitting stations that are seeking new access to available network bandwidth can achieve practical, respective, maximum bandwidth utilizations for their transmission.
Generally describing this transmission-limit role, when a station that forms part of a BSS group in a transmission network gains bandwidth access for communication in any one of several possible categories of priority, following the receipt of a transmission budget from an access point (AP) computer that is also part of the same BSS group, it is typical that it takes an appreciable number of successive inter-beacon broadcast intervals for that station to build-up its own, respective transmission limit. During the time that such a build-up is occurring, the particular station involved is not maximally utilizing its capability for communication transmissions over the network. Over time, and where a very large number, for example, of stations are involved, this build-up process can be seen to be a relatively slow process which results in a certain amount of communication inefficiency in the system.
The present invention addresses this issue by providing a special algorithm for use within each station in a BSS group, and within each transmission priority category, which algorithm creates an opportunity for, and promotes as appropriate, very rapid build-up of transmission limits so that the communicating efficiency of a station, once it has gained communication access to the network, is greatly improved, and bandwidth utilization by that station is significantly enhanced.
Fundamentally, the present invention accomplishes the objective of rapid build-up in a station's transmission limit by allowing that station, essentially at the point in time where it gains communication access to the network, to start with a transmission memory, and thus a transmission limit, of a defined, pre-selected percentage (above- 0 percent) of the most recently announced transmission budget. While a different percentage value within a range (described below herein) may be chosen to suit different applications, the percentage value of about 80-percent has been found to be very satisfactory in most applications. Accordingly, the present invention is described and illustrated herein in a setting where that 80-percent value is employed.
Additionally, and while the transmission-limit setting features of the invention may be employed readily in different specific network arrangements, these features are particularly described herein in a form of wireless, packet-based network communication environment which includes a special system for the overall management of BSS station prioritized access to available, unused bandwidth—an environment wherein implementation and practice of the present invention have been found to offer particular utility.
In such a managed-access environment, bandwidth-access flows from the periodic delivering of reports, called “beacons”, to all of the BSS-associated, network-using stations. Time-successive beacons define successive time intervals during each of which the various stations are permitted to transmit communications (typically in packets). In these intervals, the AP (in the BSS group), which functions as a controller that has direct access to the particular network with respect to which all stations in the group operate, and which thus is effectively a port to the network for all stations in the BSS group, announces, as being accessible, a certain amount of available unused bandwidth (the “transmission budget”), which amount is intentionally “stated” (in the announcements) to be less than the true, full amount of available bandwidth. The undisclosed difference acts as a reserve of available bandwidth capacity.
In a regular periodic manner (beacon intervals), the AP station broadcasts to all stations in the associated BSS the above-referred-to beacons. Each beacon advises all such stations in the BBS about the then-available, so-called transmission budget which reflects, but doesn't totally state, the amount of then-available, unused bandwidth. From beacon-to-beacon, and over time, the maximum available unused bandwidth (the transmission budget) changes in accordance immediate-prior network communication activity, and so, the amount of bandwidth which is announced to be available in each such beacon transmission will change from time-to-time, depending upon such activity. All stations within the BSS may compete, during the next-following beacon interval, for such available, announced, unused bandwidth. The reserved bandwidth is made available only to “currently transmitting” stations. As will become apparent, the present invention, in this setting, plays an important enhancement role regarding the manners in which BSS stations which are not the currently transmitting stations can most effectively and efficiently gain shared access to this announced bandwidth.
In the particular representative network now being described, this role of the present invention cooperates very effectively, in relation to maximizing the overall quality of communication service in the network, with the beacon practice just outlined, whereby existing, “currently transmitting” stations are allowed a certain deferential treatment with regard to access to available bandwidth (the unannounced bandwidth), so that the network does not compromise communication quality by failing either to recognize the fact that a currently communicating station may (a) need some additional bandwidth to complete transmission activity in which it is already engaged, or (b) need such additional bandwidth to deal with the possibility that a currently transmitting station has had certain recently attempted communications fail by virtue of some kind of a communication error.
This access-differentiating behavior is actually implemented by the participating BSS stations themselves which act in a kind of self-governing manner relating to how they seek access to available bandwidth. Those stations which are not “currently” in the immediate above-mentioned (a) and (b) situations, and which wish to obtain transmission bandwidth access during a current, new beacon interval, establish for themselves, and in a manner determined by practice of the present invention, an appropriate, requestable transmission bandwidth, referred to herein as a transmission “limit”. Those “currently transmitting” stations, however, are allowed to establish appropriately larger transmission “limits”, thus to be self-enabled to request more of the actual additional available bandwidth including the unannounced, reserved bandwidth. The amount of such reserved bandwidth is based, in part, upon prior system-activity history, from which history the AP station performs a calculation (set forth below) relating to how much of the total available, unused bandwidth to “announce” for the transmission budget.
As will be seen, and according to the invention, when a currently non-transmitting station seeks bandwidth access, and under circumstances where, after it first attempts to gain such access, it is determined to be the sole such station seeking this access, that station is permitted to progress its access with a specially elevated transmission limit—a situation which then allows that newly entering station to build up rapidly to its full, allowable transmission-limit. Rapid build-up greatly increases the operating efficiency of that station. In situations where more than one non-currently-transmitting station have tried simultaneously to gain access, none of these is permitted to use the invention's rapid build-up approach. Instead, these plural, newly “competing” stations are constrained to build-up their respective transmission limits in the conventional, “slow” build-up manner. In the conventional, slow build-up mode of operation, a newly entering station begins with a transmission limit of 0.